Simulation of Nonlinear Coaxial Line Using Ferrite Beads

Furuya, Seizo; Matsumoto, H.; Fukuda, Hitoshi; Ohboshi, Takao; Takano, Shinya; Irisawa, Juichi

doi:10.1143/jjap.41.6536

Cited by 10 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As can be seen from the results of our measurements (as well as from the data presented in quite a number of other experimental papers, e.g. [2,4,6,9], the oscillation frequencies observed in the NLTLs partially fi lled with a ferrimagnetic material clearly demonstrate dependences on sizes of the line's constituent parts. As it occurs in practice, the outerto-inner diameter ratio of the standard ferrite rings is close to 1.6 or 1.7.…”

Section: Resultssupporting

confidence: 81%

“…A critically essential feature of this technology is the employment of such transmission lines whose topology allows propagation of uni-polar (roughly speaking, d.c.) voltage pulses. Falling into this category are planar strip lines and coaxial cables (along with lumped parameter, discrete cell circuits that will not be discussed here) [3,6]. Quasi-periodic temporal variations in the values picked up by voltage sensors are observed, in particular, in coaxial cables whose cross-sections are partially fi lled with a magnetically saturated ferrimagnet.…”

Section: Introductionmentioning

confidence: 99%

“…Ò. 26, ¹ 3, 2021 high enough pulsed voltage, thus inducing a magnetic fi eld vector transverse with respect to the magnetization vector at saturation [3,4,6]. As a result, the magnetization vector demonstrates precession about the direction of the external magnetic bias, which effect is often considered to be the one and only reason for the appearance of oscillations in voltage and current in the line (i.e., in the electric and magnetic fi eld strengths).…”

Section: Introductionmentioning

confidence: 99%

“…As a result, the magnetization vector demonstrates precession about the direction of the external magnetic bias, which effect is often considered to be the one and only reason for the appearance of oscillations in voltage and current in the line (i.e., in the electric and magnetic fi eld strengths). Meanwhile, by appealing to the magnetic precession alone one does not seem to be able to interpret some essential dependences shown by the oscillations [6,7,9], like frequency versus the outer conductor diameter, or size of the ferrite insert. This paper is yet another attempt at clarifying the physics that underlies appearance of quasi-periodic fi eld strength variations in the course of propagation of unipolar pulses through a transmission line of nonuniform cross-section, showing a nonlinear response to an external excitation.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Pulsed Power to Microwaves Conversion in Nonlinear Transmission Lines

Karelin

Korenev

Krasovitsky

et al. 2021

Radio phys. radio astron.

View full text Add to dashboard Cite

Purpose: Experimental results and numerical simulations are presented, concerning effects of microwave generation in coaxial transmission lines which are fed with unipolar, high voltage electric pulses. The work is aimed at clarifying the relative importance of several mechanisms that could be responsible for the appearance of microwave-frequency oscillations in the course of pulse propagation through the guiding structure. Design/methodology/approach: Dispersive and filtering properties of coaxial waveguides that involve three structural sections are discussed. These latter follow one another along the axis of symmetry. Two identical sections at the input and output are filled with an isotropic liquid dielectric, while the middle part may, in addition, be either partially or fully filled with a non-conductive gyrotropic material. The inserted core represents a set of ferrite rings showing a nonlinear response to the initial high voltage, pulsed excitation. Throughout the series of measurements, the diameters of the inner conductor and of the ferrite core were kept constant. The outer conductor’s diameter was varied to permit analysis of the effect of that size proper and of the degree to which the cross-section is fi lled with ferrite. The gyrotropic properties of the ferrimagnetic material were realized through application of a magnetic bias field from an external coil. The measurements were made for a variety of pulsed voltage magnitudes from the range of hundreds of kilovolts, and magnetic bias fields of tens kiloamperes per meter. Findings: As observed in our experiments, as well as in papers by other writers, a unipolar pulse coming from the radially uniform front-end section, further on gives rise to quasi-monochromatic voltage oscillations. These appear as soon as the pulse has advanced a sufficient distance into the radially nonuniform portion of the guide. The oscillations may consist of a small number of quasi-periods, which suggests a large spectral line width. However, by properly selecting geometric parameters of the wave guiding line and the characteristics of the initial pulsed waveform it proves possible to obtain output frequencies of about units of gigahertz and pulse powers at subgigawatt levels. Conclusions: The frequencies and amplitudes of the appearing oscillations, as well as their spectral widths, are governed by the complex of dispersive and non-linear properties of the guiding structure. The diameters of the inner and outer coaxial conductors in the line, diameter of the ferrimagnetic insert and its intrinsic linear dispersion determine the set of waveguide modes capable of propagating through the line. An oscillating part of the waveform may appear and get separated from the main body of the pulse if it has originated at a higher frequency than the cut-off value for a different mode than the initial TEM. Key words: unipolar pulse, coaxial transmission line, microwave frequency oscillations, dispersion laws, waveguide modes

show abstract

Section: Resultssupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Pulsed Power to Microwaves Conversion in Nonlinear Transmission Lines

Karelin

Korenev

Krasovitsky

et al. 2021

Radio phys. radio astron.

View full text Add to dashboard Cite

show abstract

“…The rectangular voltage pulses applied to the gap were generated by a 100-cm-long coaxial-type ferrite sharpener. 7,8) Figure 3 shows the electrical circuit used to generate I. Voltages were measured using a Tektronix high-voltage probe (P6015A) and a Hewlett-Packard digital oscilloscope (HP54542A).…”

Section: Methodsmentioning

confidence: 99%

Rail Gap Switch Using Porous Metal as Electrode

Furuya¹,

Tanaka²,

Takano³

et al. 2005

Jpn. J. Appl. Phys.

Self Cite

View full text Add to dashboard Cite

For multichannel gap switches, the shorter the formative and statistical time lags of each gap, the larger the number of arc channels. As we examined the breakdown characteristics of a sphere/plane gap using a mirror-finished brass plate and a porous metal as plane electrodes, we confirmed that formative and statistical time lags decrease when porous metals are used as a discharge electrode, so we expect that the number of arc channels increases when porous metal is used as one of the electrodes of a rail gap. We compared experimental results to confirm this. As a result, in the case of a gap length of 1 mm, the number of arc channels increases when porous metal is used as an electrode.

show abstract

Analysis of the sharpening effect in gyromagnetic nonlinear transmission lines using the unidimensional form of the Landau–Lifshitz–Gilbert equation

Greco

Rossi

Barroso

et al. 2022

Review of Scientific Instruments

View full text Add to dashboard Cite

Continuous nonlinear transmission lines (NLTLs), also known as gyromagnetic lines, consist of ferrite-based magnetic cores biased by an external magnetic field. Over the past years, many analytical and experimental studies have predicted the rise time reduction of the input pulse to the range of a few nanoseconds or even hundreds of ps experimentally observed in such gyromagnetic lines. This effect, known as pulse sharpening, is investigated in this paper built on a model based on a periodic structure of inductive–capacitive cells in series with magnetization-driven voltage sources expressed by the one-dimensional form (1D) of the Landau–Lifshitz–Gilbert (LLG) gyromagnetic equation. We explore the model through parametric study under various input–pulse parameters to understand the physics behind the ferrimagnetic material responses. Moreover, the numerical results obtained from computational simulations using Mathematica (v. 12.1) show how the line parameters (input voltage, damping constant, saturation magnetization, and length) affect the sharpening effect, which is quantified by the switching time. Our results on ferrite-loaded coaxial lines have confirmed many results found in the literature. We validated with a good agreement the proposed model with the result obtained by Dolan in 1993 using the same 1D form of the LLG equation, thus showing that the model proposed here is suitable to quantify the sharpening effect produced by a gyromagnetic NLTL.

show abstract

Simulation of Nonlinear Coaxial Line Using Ferrite Beads

Cited by 10 publications

References 1 publication

Pulsed Power to Microwaves Conversion in Nonlinear Transmission Lines

Pulsed Power to Microwaves Conversion in Nonlinear Transmission Lines

Rail Gap Switch Using Porous Metal as Electrode

Analysis of the sharpening effect in gyromagnetic nonlinear transmission lines using the unidimensional form of the Landau–Lifshitz–Gilbert equation

Contact Info

Product

Resources

About